This invention relates generally to center pivot irrigation apparatus, and specifically to such apparatus which is electrically controlled, water powered and reversible.
Modern grain farming is an advancing technology which requires skills and equipment unheard of even thirty years ago. Irrigation, of course, is not per se the result of modern technology, but recent developments in apparatus and methods have found great acceptance due to increased efficiency, dependability and labor saving characteristics. In those areas of the world with suitable topography, center pivot irrigation has become almost a necessity for volume production of high quality grains.
Generally, center pivot systems include a fixed vertical standpipe located in the center of the area to be irrigated, with an underground water input conduit in fluid communication with one end of the standpipe and a traveling water sprinkling apparatus pivotally affixed to the other end of the standpipe. The sprinkling apparatus is made up of a multiplicity of in-line conduits supported at intervals by moving towers which propel the conduits in a circular manner about the standpipe. Obviously, a major difficulty with such a system is the control of movement of the various towers to keep the in-line conduits within relative alignment and thus prevent breakage or damage to the apparatus.
Another problem which has been encountered is due to the selection of motive means for the towers. Many systems on the market today employ high voltage electric motors at each tower to selectively drive the wheels which support the towers. While electric motors are fairly easy to accurately control, the voltage and amperage heretofore found necessary have proven to be lethal and extremely dangerous, especially around water sprinkling operations. One such electrical system is shown in U.S. Pat. No. 2,628,863.
A more acceptable approach to tower drive systems is through the use of fluid powered motors. Fluid systems are very reliable, efficient and safe to operate. U.S. Pat. No. 3,352,493 shows a water driven tower peripherally related to that to be described herein.
A third important problem encountered by designers of center pivot systems is control of the movement of the apparatus so that it can advantageously irrigate fields having a semi-circular configuration. More specifically, many farmers have buildings in one segment of the circular irrigation area and must have a system that will reverse when it reaches the edges of the field adjacent the buildings.
U.S. Pat. No. 3,314,608 shows a water powered system which is reversed in direction by manually changing the direction of water flow from the sprinkler heads. While this does provide a solution to the problem, it has obvious disadvantages in the excessive time required to make the reversal, and to observe when the reversal is necessary.
The invention to be described below presents practical solutions to the above-mentioned problems of center pivot irrigation by providing a water powered, electrically controlled reversible sprinkling apparatus.